Don't get me wrong ERC. If the Government of Canada wants to provide health services to less developed countries through the use of floating "mercy" hospitals, I have no problem so long as it's done by civilians, under the aegis of Foreign (I positively hate calling it "Global") Affairs and is paid from the foreign aid budget - not the military.
I have to say, that would be a new development in world affairs. The two organizations you refer to (Project Hope and MercyShips Organization) are religiously funded organizations that are NGO. I am not aware of any government run similar organization that provide such service, and for good reasons: For a government to go and operate in another country is much more complex to organize than a NGO. You need permission from the other state government, inter-government coordination, consideration for the existence or not of disputes between government, influence of ex-colonial status or not, or interference from other foreign government for their own purpose, etc. etc. You make the "mercy" ship military and you just doubled the complexity of making arrangements. (If you think that providing needed health care to its citizens takes priority over maintenance of at least the appearance of legitimately governing the country by overtly "lording-it" over the rich Western democracy government offering aid for the "presidents for life" of those "democracies", you are deluding yourself.)
Actually, NSO, there is no problem with an "orphan" class if, and only if, the contribution of the class is of such value to the fleet as to justify the extra cost. A good example was the AOR's before they were retired (and same when we get the two Berlin's), which were the last two steamships in the fleet. So you had to keep a full set of "everything steam" on each coast.
Orphan class costs a lot more per ship to maintain. Think set of plans. One per class to keep up to date. Same cost for an orphan as a full class, but per ship, the plans of the large class get divided by the number in the class. Same for stocks of IOR items that would otherwise restrict a ship alongside. Example: anchor. Sounds benign, but you are not allowed to sail without your full complement of anchors. Sure, you very, very seldom need an anchor replaced, but when you do, it is extremely important to be able to replace immediately. So, emergency stocks are kept in store as long as a class of ships is in service. However, that means that for an orphan class, you may keep one in stock for the individual ship, while for a full class of, say, seven ships on one coast, you will only keep two in stock.
Multiply that by all similar type of items and keeping an orphan becomes much more expansive than full class. So, again, it matters then that the force multiplication such orphan ship provides you for your operation makes it worthwhile. An Hospital ship is definitely NOT in that category.
And W601, I'll reiterate what I said just above here: We must keep in mind that there is a name for taking military forces (of any size or description) into another country without that country's government permission: It's called an invasion and it is an act of war. Just because we happen to be Canadians and have good intentions will not change that. So the question becomes: In the next, say 35 years, how often do we expect to have major disasters occurring in foreign countries or localized wars lead to cease-fires but lengthy peace negotiations requiring peacekeeping, for which the foreign government will ask for or accept the offers of Canadian military assistance? Then is such a number high enough to warrant the expenditure of funds, or is there a cheaper way to provide the same assistance? Canadians wanting the CF to do more disaster relief and peacekeeping is irrelevant without the "receiving" nation giving permission.
My gut feeling is that it is a very small number, bordering on zero.